The present invention relates generally to the art of depositing tin oxide films, and more particularly to the art of depositing low resistivity tin oxide films by thermal decomposition of alkyltinfluoride compositions.
Gillery U.S. Pat. No. 3,677,814 teaches a process for forming electroconductive tin oxide films by pyrolyzation of organic tin compounds which have direct tin-fluoride bonds, e.g., dialkyltin difluorides. Preferably a solution of 10 to 65 percent by weight dialkyltin difluoride in a polar solvent is applied to the surface of a refractory substrate at a temperature greater than about 400.degree. F. (about 204.degree. C.). Spraying a solution comprising 450 grams per liter dibutyltin difluoride, 155 milliliters per liter of triethylamine solvating agent and the balance methanol solvent onto a sheet of clear glass heated to about 1300.degree. F. (about 704.degree. C.) produces a tin oxide film about 270 nanometers thick which contains no haze or texture and exhibits a resistivity of about 15 to 20 ohms per square.
Wagner U.S. Pat. No. 4,322,363 teaches a method for making dibutyltin difluoride by reacting dibutyltin diacetate with hydrogen fluoride in water or methanol.
It has been postulated that dibutyltin difluoride may have a quasioctahedral symmetry structure around the metal atom with bridging fluorines giving rise to a two-dimensional polymeric network in which the trans-butyl groups lie along a local four fold rotational axis through the metal atom.